Add a warning for missing '#pragma pack (pop)' and suspicious uses

of '#pragma pack' in included files

This commit adds a new -Wpragma-pack warning. It warns in the following cases:

- When a translation unit is missing terminating #pragma pack (pop) directives.
- When entering an included file if the current alignment value as determined
  by '#pragma pack' directives is different from the default alignment value.
- When leaving an included file that changed the state of the current alignment
  value.

rdar://10184173

Differential Revision: https://reviews.llvm.org/D35484


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@308327 91177308-0d34-0410-b5e6-96231b3b80d8

12 files changed, 112 insertions, 19 deletions

diff --git a/test/OpenMP/declare_simd_messages.cpp b/test/OpenMP/declare_simd_messages.cpp
index 15971eb14d..af46283f9a 100644
--- a/test/OpenMP/declare_simd_messages.cpp
+++ b/test/OpenMP/declare_simd_messages.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple=x86_64-pc-win32 -verify -fopenmp -x c++ -std=c++11 -fms-extensions %s
+// RUN: %clang_cc1 -triple=x86_64-pc-win32 -verify -fopenmp -x c++ -std=c++11 -fms-extensions -Wno-pragma-pack %s
 
 // expected-error@+1 {{expected an OpenMP directive}}
 #pragma omp declare
diff --git a/test/PCH/pragma-pack.c b/test/PCH/pragma-pack.c
index 47a5570023..7b45e045b3 100644
--- a/test/PCH/pragma-pack.c
+++ b/test/PCH/pragma-pack.c
@@ -1,21 +1,21 @@
 // Test this without pch.
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DSET
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DRESET
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DPUSH
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DPUSH_POP
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DPUSH_POP_LABEL
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DSET
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DRESET
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DPUSH
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DPUSH_POP
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DPUSH_POP_LABEL
 
 // Test with pch.
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DSET -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DSET -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DRESET -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DRESET -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP_LABEL -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP_LABEL -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DSET -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DSET -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DRESET -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DRESET -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP_LABEL -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP_LABEL -verify -include-pch %t
 
 #ifndef HEADER
 #define HEADER
diff --git a/test/PCH/suspicious-pragma-pack.c b/test/PCH/suspicious-pragma-pack.c
new file mode 100644
index 0000000000..01a66af34b
--- /dev/null
+++ b/test/PCH/suspicious-pragma-pack.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -verify -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -verify -include-pch %t
+
+#ifndef HEADER
+#define HEADER
+#pragma pack (push, 1)
+#endif
+// expected-warning@-2 {{unterminated '#pragma pack (push, ...)' at end of file}}
diff --git a/test/Parser/pragma-options.c b/test/Parser/pragma-options.c
index d168a2751a..a35f0b087e 100644
--- a/test/Parser/pragma-options.c
+++ b/test/Parser/pragma-options.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -Wno-pragma-pack -fsyntax-only -verify %s
 
 /* expected-warning {{expected 'align' following '#pragma options'}} */ #pragma options
 /* expected-warning {{expected '=' following '#pragma options align'}} */ #pragma options align
diff --git a/test/Parser/pragma-options.cpp b/test/Parser/pragma-options.cpp
index 84cd38dfb3..8f5a2152c7 100644
--- a/test/Parser/pragma-options.cpp
+++ b/test/Parser/pragma-options.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -Wno-pragma-pack -fsyntax-only -verify %s
 // expected-no-diagnostics
 
 class C {
diff --git a/test/Parser/pragma-pack.c b/test/Parser/pragma-pack.c
index 0859f4157c..d2aefaa888 100644
--- a/test/Parser/pragma-pack.c
+++ b/test/Parser/pragma-pack.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wno-pragma-pack -verify %s
 
 // Note that this puts the expected lines before the directives to work around
 // limitations in the -verify mode.
diff --git a/test/Sema/Inputs/pragma-pack1.h b/test/Sema/Inputs/pragma-pack1.h
new file mode 100644
index 0000000000..40e7ad18b2
--- /dev/null
+++ b/test/Sema/Inputs/pragma-pack1.h
@@ -0,0 +1,23 @@
+
+#ifdef SET_FIRST_HEADER
+#pragma pack (16)
+#ifndef SET_SECOND_HEADER
+// expected-note@-2 2 {{previous '#pragma pack' directive that modifies alignment is here}}
+#else
+// expected-note@-4 1 {{previous '#pragma pack' directive that modifies alignment is here}}
+#endif
+// expected-warning@+3 {{non-default #pragma pack value might change the alignment of struct or union members in the included file}}
+#endif
+
+#include "pragma-pack2.h"
+
+#ifdef SET_SECOND_HEADER
+// expected-warning@-3 {{the current #pragma pack aligment value is modified in the included file}}
+#endif
+
+#ifdef PUSH_POP_FIRST_HEADER
+// This is fine, we don't change the current value.
+#pragma pack (push, 4)
+
+#pragma pack (pop)
+#endif
diff --git a/test/Sema/Inputs/pragma-pack2.h b/test/Sema/Inputs/pragma-pack2.h
new file mode 100644
index 0000000000..11036133a1
--- /dev/null
+++ b/test/Sema/Inputs/pragma-pack2.h
@@ -0,0 +1,6 @@
+
+#ifdef SET_SECOND_HEADER
+#pragma pack (8) // expected-note 2 {{previous '#pragma pack' directive that modifies alignment is here}}
+#endif
+
+struct S { int x; };
diff --git a/test/Sema/pragma-pack.c b/test/Sema/pragma-pack.c
index e93ce42148..84a946368f 100644
--- a/test/Sema/pragma-pack.c
+++ b/test/Sema/pragma-pack.c
@@ -25,3 +25,8 @@
 #pragma pack(pop, 16)
 /* expected-warning {{value of #pragma pack(show) == 16}} */ #pragma pack(show)
 
+
+// Warn about unbalanced pushes.
+#pragma pack (push,4) // expected-warning {{unterminated '#pragma pack (push, ...)' at end of file}}
+#pragma pack (push)   // expected-warning {{unterminated '#pragma pack (push, ...)' at end of file}}
+#pragma pack ()
diff --git a/test/Sema/suspicious-pragma-pack.c b/test/Sema/suspicious-pragma-pack.c
new file mode 100644
index 0000000000..10c4167102
--- /dev/null
+++ b/test/Sema/suspicious-pragma-pack.c
@@ -0,0 +1,44 @@
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DSAFE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DSAFE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DRESET_HERE -DSAFE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DSET_FIRST_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DRESET_HERE -DSET_FIRST_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -DSET_FIRST_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -DSET_SECOND_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -DSET_FIRST_HEADER -DSET_SECOND_HEADER -DWARN_MODIFIED_HEADER -verify %s
+
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I %S/Inputs -DPUSH_POP_FIRST_HEADER -DSAFE -verify %s
+
+
+#ifdef SAFE
+// expected-no-diagnostics
+#endif
+
+#ifdef PUSH_HERE
+#pragma pack (push)
+#endif
+
+#ifdef PUSH_SET_HERE
+#pragma pack (push, 4) // expected-note {{previous '#pragma pack' directive that modifies alignment is here}}
+// expected-warning@+8 {{non-default #pragma pack value might change the alignment of struct or union members in the included file}}
+#endif
+
+#ifdef RESET_HERE
+#pragma pack (4)
+#pragma pack () // no warning after reset as the value is default.
+#endif
+
+#include "pragma-pack1.h"
+
+#ifdef WARN_MODIFIED_HEADER
+// expected-warning@-3 {{the current #pragma pack aligment value is modified in the included file}}
+#endif
+
+#ifdef PUSH_SET_HERE
+#pragma pack (pop)
+#endif
+
+#ifdef PUSH_HERE
+#pragma pack (pop)
+#endif
diff --git a/test/SemaObjC/Inputs/empty.h b/test/SemaObjC/Inputs/empty.h
new file mode 100644
index 0000000000..8b1a393741
--- /dev/null
+++ b/test/SemaObjC/Inputs/empty.h
@@ -0,0 +1 @@
+// empty
diff --git a/test/SemaObjC/suspicious-pragma-pack.m b/test/SemaObjC/suspicious-pragma-pack.m
new file mode 100644
index 0000000000..125ce1d4cc
--- /dev/null
+++ b/test/SemaObjC/suspicious-pragma-pack.m
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -I%S/Inputs -verify %s
+
+#pragma pack (push, 1) // expected-note {{previous '#pragma pack' directive that modifies alignment is here}}
+#import "empty.h" // expected-warning {{non-default #pragma pack value might change the alignment of struct or union members in the included file}}
+
+#pragma pack (pop)